Vintage Def Leppard Brassart Metal Patch with Studs. Approximately 72mm x 90mm (2.75" x 3.5").
It is a thin sheet of metal with holes in the corner for the studs (4 supplied) to fix it to a jacket. The picture is printed directly onto the metal. They are very rare these days, as they were only made for a short while in the 80's